The present invention relates to waveguide hybrids and mixers and pertains particularly to an improved orthogonal hybrid-T fin-line mixer capable of both single- and double-balanced configuration.
Microwave junctions are widely used in radar technology as power dividing, summing and differencing networks. They are used in one form or another in most of the microwave components and subsystems.
Many forms of waveguides and mixers have been developed over the years. Among the waveguide hybrids that have been developed are the orthogonal hybrid-T which has been developed as a more compact structure than a standard magic-T. The orthogonal hybrid-T forms a very compact device and in operation one RF energy is fed into the H-arm while another is fed into the E-arm. Each signal couples through its respective iris into a common cavity where the signal is split equally into two H-plane waveguide outputs. The two output signals have the same phase relationship as that of a magic-T.
The present invention is aimed at providing an improved Ka-band mixer. The mixer should be able to take advantage of low cost printed circuit fabrication technology which is particularly suited to batch processing and which facilitates the use of low parasitic beam lead diodes. Furthermore, simple circuit mounting via split block constructed housing should preclude the need for multiple complex machined parts, thus further reducing fabrication cost as compared to the traditional all waveguide mixer with whisker contacted honeycomb Schottky diodes.
The invention should also lead to fully integrated multifunctional down converters which can readily include a local oscillator, low noise amplifier, antenna, appropriate preselection and postselection filters, or other integrated circuitry which complement the down converter assembly. Integrated receivers using monolithic or millimeter wave integrated circuitry should be under particular attention due to the inherent small size and low production cost. This benefit should offer considerable advantages when mechanizing multichannel receivers for applications where space is a premium.
Thus, the design approach should yield production economy due to ease of manufacturing and should be compatible to microwave and millimeter wave integrated circuit technology using suspended stripline, microstrip, coplanar and slot line where air and metallized dielectric substrate can be the primary media.